Remove outdated cluster/charts/rook-ceph/.gitignore
Remove outdated cluster/charts/rook-ceph/.gitignore

Since values.yaml is no longer generated from a template
thanks to #3701, the .gitignore file shouldn't be needed.

Signed-off-by: Kristoffer Grönlund <8d116301f44f67d979af4b34089c9b5aef6e1b33@suse.com>

rook/rook,rook/rook,rook/rook,rook/rook,rook/nfs,rook/nfs,rook/nfs,rook/rook